On an aircraft, for example a transport aircraft, a fuel system of the aircraft, which is intended to supply fuel to an engine of the aircraft from at least one fuel tank, generally includes a fuel return system.
The fuel return system includes a fuel return valve (FRV) of the FRV type which is arranged on a return line. The return line is intended to be installed between the engine of the aircraft and the fuel tank of the aircraft.
This return system allows hot fuel to be returned from the engine to the fuel tank or tanks. The return valve must be open to allow return of the fuel. When the return valve is closed, the return path is closed and fuel cannot be returned to the tank of the aircraft.
The fuel return valve of a fuel return line requires a high pressure in order to operate. Such a pressure can only be generated when the engine is running. If the return valve is designed to be in the closed position when the engine is not in operation, no path for evacuation of the fuel can be provided in such a situation using this standard architecture.
Consequently, the fuel return valve is configured to be able to be opened and allow a return of fuel from the engine to the fuel tank when the engine is in operation; and to be closed and prevent a return of fuel from the engine to the fuel tank when the engine is not in operation.
However, after stoppage of the engine, the heat from the engine increases the pressure in a fuel circuit system. When the pressure reaches a critical value, the fuel must be evacuated from the fuel circuit system. To do this, the simplest and cheapest solution is to evacuate fuel to the atmosphere. The certification authorities do not, however, allow evacuation of fuel to the atmosphere. Thus, there is a need for developing an enhanced fuel path control system.